It is generally said that Mechanical castings are done by the green or dry sand mould while Fine arts castings by the baking mould. The writer believes that even for mechanical castings, the baking mould method which is hereditary in Japan could sometimes be usefully applied ; however the practical example has been very few.
  The writer tried to apply a kind of baking mould methods on aluminium casting in a factory under his direction and had a successful result in reducing the rates of incomplete casting from 60% to 15%. The process is described in this paper.

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  Results of our various experiments conducted for prevention of sand sticking on patterns in molding operation are herewith set forth as under :
  (1) Chemical and wax treatments on the surfaces of patterns decrease the sticking sand.
  (2) If finishing of pattern surfaces is too smooth, stickiness of sand increases.
  (3) Preheating on patterns prevents adhesion of sand.
  (4) Wood patterns cause more adhesion of sand than metal patterns.
  (5) Characteristic U-shaped curves were obtained between stickiness and moisture content of sand. If moisture content of sand is within the limits, stickiness of sand is at the lowest, but it below or above its limits, it increases considerably.

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  Linear rates of solidification shrinkage of pure aluminium and alminium alloys were measured. These values are determined by (L−L'/L ×100)% when L is length of test mould and L' is length of test piece which is cast in this test mould. The order of magnitude of these values is pure aluminium (biggest) super-duralumin, lautal and silumin-gamma. This tendency coincides with the experience in our foundry operation.
  Abont pure metals it is possible to calculate coefficient of linear thermal expansion by the linear rate of solidification shrinkage and temp.-difference of solidification temp. and room temp. But about alloys it is impossible to calculate by temp.-difference of liquidus or solidus point and room temp.
  For this purpose I propose correction for solidification point. This corrected solidification point is sum of temp. of solidus point and one-third of temp.-difference of liquidus and solidus, I believe it become possible to calculate correctly coefficient of linear thermal expansion of alloys by temp.-difference of corrected solidification point and room temp.

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